It doesn't mean Internet filtering is outlawed, it only means that ISPs cannot be forced to do it. They are free to do filtering if they themselves wish to, like e.g. if they get enough money from MAFIAA-like entities to do it.

It is still an important decision given the fact that those aforementioned entities have been trying to force ISPs to do filtering, even when the ISPs themselves do not wish to do it. This releases those ISPs unconditionally from such. Also, it could possibly pave the way for actual outlawing of most Internet traffic, though I highly doubt it would mean all of it.

Expect some ISPs now to actually start advertising that they offer unfiltered Internet access if some of the other ISPs in the same country/area make a deal with MAFIAA et. al. and start filtering. It will become a selling point now that there is no worry about MAFIAA coming after them.